Wastegate: Service and Repair

11 65 580 - Replacing vacuum unit (wastegate valve) (N54)





Important!
Overpressure and vacuum lines are identified by the size of the seals and colour-coded Red and Blue and must not be mixed up with each other.
Build up pressure with Blue colour.
Generate vacuum pressure with Red colour.
Check ease of movement between turnbuckle and pin of adjusting lever (ensure rectangularity).





Note on ordering:
- Workshop equipment
- Workshop planning
- Workshop equipment catalogue
- Measuring and test equipment
- No. 81 29 0 426 464






Necessary preliminary tasks:
- Prepare BMW diagnosis system
- Start diagnosis program
Perception: -
1. - Noises at turbocharger (clanking)
or - Fault memory entry:
1. - Drive
2. - Engine electronics
3 - Air supply
4. - Boost pressure control
- Remove both exhaust turbochargers





Release locking clip (2).
Disengage linkage of vacuum unit (wastegate).





Release screws (1 and 2).
Tightening torque 11 65 11AZ [1][2]Specifications.

Installation Note:
Replace vacuum unit (wastegate).





Adjusting vacuum unit (wastegate) linkage:
Initial position of vacuum unit wastegate (linkage) depressurized.
Connect red vacuum line (1) to vacuum unit (wastegate).





Vacuum pressure measurement:
Prepare BMW diagnosis system on vacuum diagnosis unit.
1. - Screw in pressure sensor.
2. - Connect 12V battery cables (2) to vehicle battery positive and negative.
3. - Connect 12V battery cables (3) to vehicle battery positive and negative (pump operation max. 3 mins.).
4. - Controller for vacuum connection.
5. - Vacuum connection (Red).





Calibration for vacuum pressure measurement:
Release lock nut on controller (1).
Press setting with measurement.
- Determine ambient pressure
- Seal stop cock (2) in direction of arrow
- Set controller (1) to 200 ± 10 mbar below ambient pressure (e.g. 980 - 200 = 780 mbar).
Open stop cock (2) again.
Wastegate valve closes.





Initial position (1) of wastegate linkage with preset vacuum pressure.
Wastegate valve virtually closed.





Checking turnability of wastegate valve.
-a)
- Wastegate valve can be turned with minimal force.
Adjustment of wastegate valve is OK.
-b)
- Wastegate valve has play and can be turned without resistance, wastegate valve open too far.
Carry out adjustment of wastegate valve, shorten linkage.
-c)
- Wastegate valve cannot be turned, wastegate valve closed.
Carry out adjustment of wastegate valve, lengthen linkage.





Adjustment at linkage:
To lengthen linkage, turn turnbuckle (1) max. 180° in counterclockwise direction.
To shorten linkage, turn turnbuckle (1) max. 180° in clockwise direction.
Engage turnbuckle (1) on adjusting lever in direction of arrow.

Important!
Check ease of movement between turnbuckle (1) and pin of adjusting lever (ensure rectangularity).

Check turnability of wastegate valve again.





Secure lock nut (1); to do so, secure turnbuckle against turning with a suitable tool.
Tightening torque 11 65 10AZ [1][2]Specifications.
Attach locking clip (2).





Assemble engine.
Observe diagnosis instructions.
Execute test module for boost pressure control.